Foot operated gas pumps



7, 1968 c. T. SUNDQUIST 3,398,885

FOOT OPERATED GAS PUMPS Filed Nov. 14, 1966 2 Sheets-Sheet l Aug. 27, 1968 c. T. SUNDQUIST FOOT OPERATED GAS PUMPS 2 Sheets-Sheet 2 Filed Nov. 14, 1966 FIG.

F l G. 3 INVENTOR United States Patent 3,398,885 FOOT OPERATED GAS PUMPS Charles T. Sundquist, 12566 SE. 53rd St., Bellevue, Wash. 98004 Filed Nov. 14, 1966, Ser. No. 594,004 1 Claim. (Cl. 230-191) ABSTRACT OF THE DISCLOSURE This invention is an improvement in two cylinder, positive displacement, foot operated gas pumps. It is operated by standing on and rocking a treadle with the feet, meanwhile steadying the body by grasping a grab bar with the hands. Improvements include a one piece treadle mounted beneath the two plunger-cylinder combinations and elastic pads for absorbing the impact of the plungers against the cylinder heads.

An object of the invention is the provision of a foot operated means of pumping gas.

An object of the invention is the provision of foot operated means of compressing air for marine propulsion.

An object of the invention is the provision of foot operated means for ventilating fallout shelters equipped with high elficiency filters for removing air borne radioactive contamination.

FIGURE 1 is a perspective view of a foot operated gas pump.

FIGURE 2 is a sectional View taken along line 22 of FIGURE 1. It shows the interior arrangement of a plunger-cylinder combination for operating in a ductwork evacuating mode.

FIGURE 3 is a sectional view taken along line 22 of FIGURE 1. It shows the interior arrangement of a plunger-cylinder combination for operating in a ductwork pressurizing mode.

This pump works well in pumping air against pressure differences in the neighborhood of 6 inches water gage and less. Materials of modest strength and rigidity can be usede.g., wood, plastic, sheet aluminum.

For small fallout shelters the pump would be arranged for air flow as in FIGURE 2, the pump being located within the living space of the shelter. An air duct would extend from gas connection 7 to an air filter and thence to a shelter air inlet. Fresh filtered air would be discharged into the living space from the bottoms of cylinders 2.

This invention is unlike that of Whitaker and an improvement because the one piece treadle is mounted beneath the cylinders. With both plungers and operator above the treadle, less headroom is required. This inven- "ice tion is more convenient because the operator does not have to climb as high above the base to get on the treadle.

This invention is unlike that of Alvik and an improvement because the treadle is one piece. The Alvik arrangement is more complicated because two combination pedal and crank pieces, a pulley wheel and cable are required to perform the same function as the treadle.

This invention is unique and an improvement in another important respect. Elastic pads are provided to absorb and soften the impact of plungers striking the cylinder heads.

An operator causes the gas pump to Work by rocking treadle 3 with his feet, meanwhile steadying himself by grasping grab bar -6 with his hands. Plungers 5 cause gas to flow through cylinders 2.

FIGURE 1 illustrates a foot operated gas pump. Plenum 1 connects two cylinders 2 to gas connection 7. Treadle 3 is pivoted from mounting frame 4, which in turn is fastened rigidly to duct work 1. Plungers 5, pivoted from treadle 3, work in and out of the two cylinders.

The internal arrangement of a cylinder is shown in FIGURE 2 and FIGURE 3. The inside walls of the cylinder are smooth. Sliding seals attached to the plunger restrict the circulation of gas between the plunger 5 and cylinder 2. Elastic pads 11 arrest the inward motion of plunger 5 at the end of its inward stroke. Valve 12 and valve 13 regulate the flow of gas into and out of the cylinder. Gas ports from valve 12 communicate with duct work 1. Gas ports from valve 13 communicate through the plunger to the space outside the gas pump. Valves 12 and 13 and elastic pads 11 are arranged to provide minimum clearance when the plunger is at the end of its inward stroke in order to provide maximum volumetric efiiciency.

The inventor claims:

1. A foot operated gas pump comprising two cylinders connected to ductwork, a mounting frame, a one piece treadle mounted beneath the cylinders, two plungers extending upward from the treadle and working in and out of the cylinders, valves to direct the flow of gas through the cylinders, elastic pads to absorb the impact of the plungers against the cylinder heads, the pump being operated by standing on the treadle and rocking it with the feet.

References Cited UNITED STATES PATENTS 133,278 1l/l872 Whitaker 103l70 FOREIGN PATENTS 73,439 11/ 1951 Denmark.

ROBERT M. WALKER, Primary Examiner. 

